IS 7069:2001 ~'-ll \ \ vmmm m `w-H (Wibq T)-fafmz ( WW?!?w) (Reaffirmed - 2012) `JlTF2-wr5xil ?mnqT `tk'Jllw$s Indian Standard BENZOTHIAZYL-2-CYCLOHEXYL SULPHENAMIDE (CBS) -- SPECIFICATION ( Second Revision) ICS 83.040.01 @ BIS 2001 BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARC NEW DELHI 110002 December 2001 Price Group 3 Rubber Products Sectional Committee, PCD 13 FOREWORD This Indian Standard (Second Revision) was adopted by the Bureau of Indian Standards, after the draft finalized by the Rubber Products Sectional Committee had been approved by the Petroleum, Coal and Related Products Division Council. Benzothiazyl-2-Cyclohexyl sulphenamide (CBS) is a well known accelerator various applications in the rubber industry. with a delayed onset of cure for It is soluble in benzene, carbon tetrachloride, acetone, ethanol and insoluble in water. In order to facilitate proper appreciation of this sulphenamide class accelerator in the rubber industry, this standard indicating chemical requirements and technological evaluation procedure has been brought out. Like all other sulphenamide class accelerators, this sulphenamide accelerator is sensitive to degradation and loss of activity on long storage periods. With time, this material degrades releasing amine and exhibiting a loss in assay and increase in methanol insoluble contents due to formation of MBTS. Use of degraded sulphenamide accelerator in rubber compounds will cause decrease in scorch safety, cure rate and state of cure. Heat, humidity and acidic conditions of storage increase the rate of degradation of sulphenamide accelerators and hence this type of material should be stored in a cool and dry place and away from any acidic material or atmosphere. This standard was published in 1973 and revised in 1986. First revision was prepared in order to include a more accurate method for determination of assay based on ultraviolet spectroscopy. In this version (second revision) description of the material has been modified. Characteristics and requirement for melting point sulphated as, volatile matter and free amine have been tightened. The characteristics for moisture has been deleted. The material being a reactive chemical, all persons concerned with handling of this chemical should be properly informed about the nature of the material, possible effect on direct contact, inhalation and accidental ingestion. The composition of the Committee responsible for formulation of this standard is given in Annex F. For the purpose of deciding whether a particular requirement of this standard is complied with the final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2 :1960 `Rules for rounding off numerical values (revised)'. The number of significant places retained in the rounded off value should be the same as that of the specified value in the standard. lS 7069 :2001 Indian Standard BENZOTHIAZYL-2-CYCLOHEXYL SULPHENAMIDE (CBS) -- SPECIFICATION ( Second Revision) 1 SCOPE This Standard prescribes the requirements and method of sampling and test for benzothiazyl-2-cy clohexyl sttlphenamide (CBS) intended for use in rubber compounding as a delayed action accelerator for vulcanization of rubber/rubber compounds. This standard is applicable for materials in pellet or powder (uncoated/coated) form. 2 REFERENCES The following Indian Standards contain provision which through reference in this text, constitute provisions of this standard. At the time of publication, the edition indicated were valid. All standards are subject to revision, and parties to agreements based on the standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below: 1S No. 1070:1992 1675:1971 3399:1993 Title Reagent grade water (third revision) Stearic acid, technical (first revision) Zinc oxide for rubber industry (second revision) density of about 1.3 (for guidance only) and shall be free from any visible impurities. The material in the form of pellets or granules or powder may contain dedusting or binding agents approximately 2.0 percent by mass. The manufacturer is required to specify the solvent to be used for extracting the coating material or binder and the material shall be made free from coating material or binder by extracting with the suitable solvent prior to testing for the requirements of methanol insoltrbles specified in Table 1. 3.2 The material shall also comply with the requirements given in Table 1 when tested according to the procedures given in COI4 of the Table 1. Table 1 Requirements of Benzothiazyl Cyclohexyl Sulphenamide (CBS) S1 Chmnetesisties No. 1-2- (1) (2) i) Melting Point, "c a) Appeamnce of first droplet, Min b) Completion of melting, ii) Sulphtited ash, percent by mass, Max iii) Copper content, ppm, Mu.s iv) Volati Ie matter, percent by mass, Max RequireMethod of `rest, Re~ to ments Annex uf `Annex of this Stwrdwd 1S 6918 (4) (3) (5) 97 ICO-107 -- -- c c F 0.3 20 0.5 0.5 -- -- A B Methods of test for vulcanized rubbers: 34X) : (Part 1): 1987 Tensile stress -- Strain properties (second revision) (Part 2): 1995 Hardness (second revision) 3660: Methods of test for natural rubber: (Part 7): 1989 Determination of Money viscosity (NR:8) (second revision) (Part 8): 2000 Mixing and vulcanizing of rubber in standard compound (NR:9) (second revision) 4588:1986 Rubber, raw natural (third revision) Mercaptobenzothiazole 6918:1972 7086 Methods of sampling and test for (Part 1): 1973 rubber compounding ingredients 8851:1994 Sttlphur for rubber industry (first revision) 3 REQUIREMENTS 3.1 Description The material shall be in the form of light cream or tan coloured pellets or granules or powder having relative 1 G v) Free amine, percent by mass, Mus vi) Assay, percent by mass, Min a) For uncoated material b) For coated/ bound material vii) Methanol insoluble, percent by mass, Ma -- c 96.0 94.0 0.5 D -- NOTE -- All tests shall be carried out within 15 days of the receipt of material by the purchaser. 3.3 Compounding The material when compounded and tested according to the procedure given in Annex E shall have performance characteristics comparable to standard material satisfying the requirements of 3.1 and 3.2. 4 PACKING 4.1 Packing The material shall be packed securely so as to avoid exposure to air, moisture and acidic atmosphere. The AND MARKING lS 7069 :2001 5.2.2 Test for all other characteristics conducted on a composite sample. 5.3 Criteria for Conformity shall be material should accompany with Material Data Supply Sheet (MSDS). The exact mode of packing shall be as agreed to between thepurchaser and the supplier. 4.2 Marking Each package shall be marked with the following: a) b) c) d) e) Name of the material; Indication of source of manufacture; Net mass of the material; Month and year of the manufacture; Lot/batch number. Marking 5.3.1 Copper The mean and range of test results for copper shall be calculated as follows: and Mean ( ~ Sum of test results ) = Number of test t'fXLtltS 4.2.1 BIS Cer~ification The packages Mark. Range (R) = Difference between the maximum and minimum value of the test results The lot shall be deemed to have requirement of the specification if ~ + 0.620R<20 5.3.2 Composite Samples satisfied the may also be marked with the Standard 4.2.1.1 The use of the Standard Mark is governed by the provisions of the Bureau of Indian Standards Act, 1986 and Lhe Rules and Regulations made thereunder. The details of conditions under which the Iicence for the use of the Standard Mark may be granted to manufacturers or producers maybe obtained from the Bureau of Indian Standards. 5 SAMPLING 5.1 The representative samples of the material shall be drawn as prescribed in IS 7086 (Part 1). 5.2 Number of Tests 5.2.1 Test for copper (see Table 1) shall be conducted on individual ~ample. In respect of all other characteristics the lot shall be considered as conforming to the specification if the composite samples satisfies each of these requirements. 6 QUALITY REAGENTS Unless specified otherwise `pure chemicals' and distilled water (see IS 1070) shall be employed in tests, NOTE -- `Pure chemicals' shall mean chemicals that do not contain impurities Which affect the results of analysis. ANNEX A [Table 1, S1 No. (iv)] DETERMINATION A-1 APPARATUS Glass petri dish, 12 cm in diameter having 40 mlcapacity. A-2 PROCEDURE Weigh 25 g accurate to 1 mg of the powdered material and spread it evenly on thOe dish. The dish is placed in an oven maintained at 65 C for one hour. The 10SSin mass is recorded. Volatile matter, percent by mass = OF VOLATILE MATTER A-3 CALCULATION A'fl-J'f2x, ~ oo Ml= mass in g of the sample taken; and M2 = mass in g of the sample after heating. ANNEX B [Table 1, S1No. (v)] DETERMINATION B-1 PROCEDURE Weigh approximately 5 g of the material accurately to 1 mg, and put in a 300-ml Erlenmeyer flask. Add 150 ml of isopropanol toluene mixture (5:3) to dissolve the material. The solvent mixture of isopropanol-tol uene 2 OF FREE AMINE should be neutralized with respect to bromophenol blue to a greenish yellow end point before use. After adding a few drops of bromophenol blue indicator the solution is titrated with O.lN hydrochloric acid till the appearance of yellow coloration. IS 7069:2001 B-2 CALCULATION Free amine percent by mass= 0.99 v ~ where V = M = volume in ml of 0.1 N hydrochloric acid used, and massing of the material taken for the test. ANNEX C [Table 1, S1No. (vi)] DETERMINATION C-1 SCOPE This work instruction is applicable for assessing the purity of different sulphenamide type of accelerators (for example CBS) used in rubber and allied industries. C-2 ABBREVIATION/DEFINITION Reducing solution -- Isopropanol/toluene saturated with hydrogen sulphide at 25°C. C-3 APPARATUS Burette (50 ml), H# trap train, magnetic stirrer, kipp's apparatus for HIS gas generation, reagent bottle, magnetic stirrer bar, stoppered con:cal flask (250 ml), glass tubing, two hole stopper, volumetric flask, safety, glasses, laboratory fume cupboard. C-4 MATERIAL Bromophenol blue indicator solution, sodium hydroxide, tris buffer, hydrochloric acid (O.lN), primary titrant (0.25 N to 0.35 N), isopropanol, toluene, ferrous sulphide, hydrochloric acid (2N), reducing solution, 12 percent NaOH solution, 25 percent NaOH solution, distilled water. C-5 METHOD Hydrogen sulphide is a toxic gas and should only be handled in a fume cupboard. The HZS trap train should be used for catching unused H# when preparing the reagent. Toluene and isopropanol are highly inflammable, should be handled with appropriate precau~ian. C-5. 1 Preparation of Reducing Solution solvent OF ASSAY Insert another pjastic tube into the same bottle through another hole in such a way so that the plastic tube will be above the level of 12 percent NaOH solution. C-5.1.2 Insert plastic tubing in 25 percent NaOH solution containing bottle and distilled water bottle respectively in the same way as 12 percent NaOH solution containing bottle. This type of connection forms HZS trap train. C-5.1.3 Add ferrous sulphide and dilute hydrochloric acid (2N) into the Kipp's apparatus. As soon as ferrous sulphide will come in contact with hydrochloric acid H,S gas generation will take place. C-5.1.4 Sparge H2S gas into isopropanol/toluene solvent. Stir the isopropanol/tol uene solvent continuously until saturation is achieved. Saturation will be indicated by an increase in bubble rate of HJS gas in the isopropanol/toluene solvent as well as yellow colour in the 12 percent NaOH solution. Store the reducing solution loosely capped at ambient temperature. C-5.2 Standardization of Primary Titrant C-5.2.1 Take 1.3- 1.5 gm TRIS buffer in a 250 ml conical flask. Add 10 ml distilled water into the conical flask and place on magnetic stirrer until the TRIS buffer get dissolved. C-5.2.2 Add 150 ml isopropanol/toluene solvent into the conical flask. Add 5 drops of bromophenol blue and titrate with the primarily titrant to the first yellow end point. Calculate the normality of the primary titrant as follows: T `$'= (VHCI)(0.121 14) where T C-5.1.1 Set Kipp's apparatus for H2S generation in a fume cupboard. Use a 1 000-ml reagent bottle for saturating isopropanol/tol uene solvent and add a magnetic stir bar. Take a two hole plastic stopper and insert the outlet tube of H# into one hole and another plastic tube into the other hole, so that the outlet tube of HZS should be below will be above the level of i.mpropanol/toluene. Set the reagent bottle onto a magnetic stirrer. Insert the outlet tube of the reagent bottle, through a two hole rubber stopper, into an empty 500-ml conical flask. Insert another plastic tube into the same flask through another hole. Insert the outlet tube of the conical flask into a bottle contain 12 percent NaOH solution through a two hole plastic stopper. Inlet tube should be below the level of the NaOH solution. v HCI 0.12114 = mass of ~S buffer, volume of hydrochloric acid required for titration, and = equivalent mass of TRIS buffer­ 1000. = C-6 PROCEDURE Take 2.0 gm homogenized accelerator sample into a 250 ml stoppered conical flask add magnetic stirrer bar. Add 50 ml isopropanol/toluene solvent, stopper and 3-. IS 7069:2001 amine with the primary titrant to the first yellow end point. Two drops of additional indicator added near the end point will intensify the colour change. Record the volume of the primary titrant as V, and use in the calculation. Determine the percent assay as follows: A= where v, dissolve by slowly stirring on magnetic stirrer (Take care not to splash solids onto the sides of flask). Allow at least 10 min stirring for complete dissolution of accelerator. Add 5 drops of bromophenol blue indicator solution and titrate the excess base with 0.1 N HC1 to the first yellow end point. Immediately after neutralizing the excess base, add 125 ml of reducing solution, replace the stopper and set aside for minimum of 90 min at ambient temperature to complete sulphenamide reduction. Complete reduction can be identified as wine or rust colour of the sample solution. While stirring rapidly with the magnetic stirrer titrate the liberated vaxvmx s Msxlm v HCI MS S = volume of primary titrant normality of primary titrant = forCBS: 0.2644. = sample mass = ANNEX D [Table 1, S1No (vii)] DETERMINATION D-1 PROCEDURE D-1.l Weigh 4 g of the material to the nearest milligram and put in a 400 ml beaker. Add 250 ml of methanol into it. Stir it at a room temperature for 30 minutes with the help of a magnetic stin-er. Allow the residue to settle. Decant the bulk of the supernatent liquid. Transfer the residue as thick slurry on to a previously weighed centred glass crucible (porosity No. 3). Wash the cake OF METHANOL INSOLUBLES two or three times with 25 ml of methanol and then suck it dry. Dry the crucible at 100"C and weigh. D-1.2 In case of granular / pellet material, the material shall be powdered before testing. D-2 CALCULATION Methanol Insoluble, residue x 25 percent by mass = mass of the ANNEX E (Clause 3.3) METHODS FOR COMPOUNDING AND TESTING OF BENZOTHIAZYL-2-CYCLOHEXYL SULPHENAMIDE (CBS) E-3 TESTS E-3.1 The tests given below are recommended for each test sample. The approved sample shall also be tested side by side using the same masterbatch, that is, compound excluding accelerator only. E-3.1.1 Mooney scorch test shall be done at 120°C in accordance with the method prescribed in IS 3660 (Part 7). E-3.1.2 Tensile strength, modulus at 300 percent elo~gation, elongation at break at different cures at 141 C (from below to above the expected optimum cure) shall be tested in accordance with the method described in IS 3400 (Part 1). E-3.1.3 Hardness on optimum cure at 141°C shall be tested in accordance with the method prescribed in IS 3400 (Part 2). WI RESULT The values obtained with the test sample shall not vary by more than 20 percent for Mooney scorch and ~ 10 percent for all the other characteristics from those obtained with the approved sample. 4 E-1 TEST COMPOUND As a guidance, the following test compound may be formance properties of used for testing benzothiazyl-2-cyciohexyl sulphenamide (CBS) in rubber compound: Parts by Mass Natural rubber, Grade A 100 (conforming to IS 4588) Carbon black, HAF Zinc oxide (conforming to IS 3399) Mineral oil (aromatic) plasticizer Stearic acid (conforming to IS 1675) Sulphur (conformingtoIS8851) Benzothiazyl-2-cyclohexyl sulphenamide (CBS) E2 COMPOUNDING 45 5 5 3 2.5 05 Follow the procedure prescribed in IS 3660 (Part 8). lS 7069 :2001 ANNEX F (Foreword) COMMITTEE COMPOSITION Rubber Products Sectional Committee, PCD 13 Organization +ar Industries Ltd. Murnbai ~11 India, Rubber Industries Association, I Representative(s) SHRJMANUM. PATEL(Chirrrsan) Mumbai SHRJ M. M. PATEL SHRJK. D. SHAH(Aftemare) ~ttuned Polymers Pvt Ltd, Mumbai SHRJMEHUL PAmL SHRI RAJENDRA INGAWALE (Alternate) Bayer India Ltd, Mumbai 13engal Waterproof Ltd, Kolkata SHJU P. K. CHATSERtEE MANAGER (Tech Service) SHJUB. BANERJEE SHRJA. K. BANDOPADHYAY (A{temare) Dunlop India Ltd, Kolkata Directorate General of Supplies & Disposals, Pvt Ltd, Kolkata New Delhi SHRJS. K. NANDI(Alfemate) SHRJSUNOER LAL SHRI A. K. JA[N (A ftemute) Escon Consultants Hinclustan SHRID. BANERJEE SHRJS. R. PANICKER SHRIJ. SAHAYAOASAN (Alternate) Latex Ltd, Thiruvanathapuram ICI India Ltd, Kolkata Indian Petrochemicals Corporation Ltd, Vadodara Thane SHJUM. K. CHATITRJEE SHJUA. K. BASU SHRJR. K. GARG (Alternate) Indian Rubber Mfrs Research J. K. Industries Ltd, Rajasthan Association, DR W. MiLLiNS (Affemate) DR M. S. BANERJEE OR R. MUKHOPADHYAY SHRI V. K. MF,RA (Alternate) Ministry of Defence (DGQA), Ministry of Foreign Trade, New Delhi SHRI A. K. BANDHOPADHYAY SHRI GAUTAMGUPTA(Ahernare) Kolkata SHRIK. J. SRIVASTAVA SHJUP. P. SAXENA (Afrernate) Modi Rubber Ltd, Meerut (U.P) MRF Ltd, Chennai National National Test House, Organic Kolkata Industries Ltd, Thane SHRI MARKAND MI'JTAL (Altemure) SHRIS. K. SHARMA SHRI ZACHARJAH GEORGE SHRI A. GEORGEJOHN (Altemare) SHRiD. N. ROY SHRJA. K.CHAKRABORN(Ahernate) SHRIC. S. lNAMDAR SHRI D. S. DESAI (Alternate) DR B. BANEJUEE DR S. CHAKRABORTY (Altemare) Chemicals Philips Carbon Black Ltd, Distt Bharuch Phoenix Yule & Co Ltd, Kolkata Kolkata Standards Institute Organization, Lucknow SHRI T. K. MUKHEJUEE DR A. GUHA (Ahemate) RAE1 Polymers, Research, SHRIB. DUITA DR S. P. MANiK Assrr lNSPECTtON ENGINEER(Alternate) Designs & The Rubber Research Sundaram Synthetics Indusries of India, Kottayam SHRIK. S. GOPALAKRJSHNAN DR M. G. KUMARAN (Ahernate) Ltd, Madurai Ltd, Mumbai Pune SHRI R. RAMAN SHRJC. GOPINATHAN (Ahemafe) and Chemicals DR R, N. MEHROTRA DR VED PARKASH(Afremate) Swastik Rubber Products, SHRI A. V. KATE (Continued on puge 6) 5 IS 7069:2001 (C(lJltiilile(ijrofrl page 5) Orgat{i:afiotl Tyre Corporation BIS Directorate of India Ltd, Kolkata General Representative SHRIB. N. BHATTACHARYYA DR SUNILKR GHOSH(A//er//are) ANJAN KAR, Director & Head (PCD) [Representing Director General (E.r-o&io Member-Secretary SHSU R. P. MMHRA )1 Joint Director (pCD), BIS Rubber Chemicals & Compounding Philips Carbon Black Ingredients Subcommittee, PCD 13:5 Ltd, Distt Bharuch ~ DR B. Bmswz (Convener) SHRJARUP MUKERJEE (Ahemafe) DR Apar Industries Ltd, Mumbai PRABHU Bata India Ltd, Kolkata Bayer (India) Ltd, Mumbai Cabot India Ltd. Mumbai Dunlop India Ltd, Kolkata Latex Ltd, Tbiruvanathapuram New Delhi Division, Hoogly SHJUS. C. MAITY(Alternate) SW Ihrwm Bmssom SHRJS. M. MrtRA (Aftemate) DR D. J. BHARUCHA SHRJP. K. CHA?TERSEE (Alfemare) SHRJP. M. JACOB SHfrtD. P. !%4HA DR A. GUHA (Alternate) Hindustan SHRJS. R. PAN[CKER SHSU J. SAHAYADASAN (Afremate) CHANDRA h Drr DINSSH SHRJONKARSINGHBHANDARI (Alternate) Hi-Tech Carbon, ICI Ltd, Chemical J. K. Industries, h h S. CHAKtWORm SHJUJ. K. BHAWACHARJEE (Alfemafe) New Delhi R. MUKHOPADHVAY DR A. S. DEURJ(Afrerrrafe) Modi Rubber Ltd. Modipuram MRF Ltd, Chennai National Phoenix Organic Chemicals Industries Ltd, Thane SHRJG. C. UPPADHYAV SHRJA. GEOROE JOHN SHRJZACHARIAH GEORGE (Akemate) SHRrC. S. INAMDAR SHRJD. S. DESAI (Alternate) Yule & Co Ltd, Kolkata Board, Kottayam SHRJT. K. MUKHERJEE DR A. GUHA (Afremafe) The Rubber Rubber SHRJ K. S. GDPAJAKIUSHNAN SHRJN. R. PEETHAMBARAN (Alternate) Products Ltd, Thane Ltd, Mumbai Ltd, Pune Smrr L~.m K. Swrrv Synthetics Swastik ~re & Chemicals Rubber Products DR R. N. MEHROTIW DR VED PRAKAW(Aftemare) SHRJA. V. KAIY SHRJB. N. BHAITACHARYA DR S. K. 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